How to Run A Psyche Serpent?

[Palanan]

I came across the psyche serpent (https://www.d20pfsrd.com/bestiary/monster-listings/magical-beasts/psyche-serpent/) from Occult Bestiary, and while I’m intrigued by the concept I’m not sure how best to implement it.

How would you set up a psyche serpent for a primarily combat-based encounter?

[Boci]

The three options seems to be:

1. It slithers up on the party while asleep, lowering their will save. The problem is, there's no reason for it to just lower their willsave. As written you can't do much, if you catches you asleep, it can just keep biting until you fail enough saves to have 0 wisdom, so you're reliant on whoever posted guard to notice

2. It manages to isolate a player and hypnotise suggestion them, but really combat though

3. Through invisibility and stealth checks (though it has no inherent bonus to stealth, it is tiny and has 16 dex, so that's +11, plus invibility twice per day). Its also CR 2, so it can be added to another encounter, striking the backlines whilst the party deals with a high damage brute monster which demands their immediate attention

[Kurald Galain]

First thing to notice is that these snakes are pretty smart.

So basically, it has decent perception so it can hear the party approach and go invisible before combat. Then go up to a rogue-ish or caster-ish looking PC (because they likely have low fort saves), bite, then spend the next round making a diplomacy check. The PC only gets a save if he made his poison save.

And then get creative with the Suggestion spell. A good Suggestion means the PC is out of combat. So don't place one snake alone, but either add one to a bunch of melee brutes, or place a bunch of snakes together at the start of a dungeon. HTH!